1. Field of the Invention
The present invention relates to a method for dehydration of a hydrous product.
More particularly, the present invention relates to a method for dehydrating a hydrous product characterized by incorporating anhydrous lactitol into the hydrous matter to convert the anhydrous lactitol into crystalline lactitol hydrate.
2. Definition
Throughout the specification, percentages and parts will be expressed by weight based on the dry solid, unless specified otherwise.
3. Description of the Prior Art
The moisture in foods greatly influences the physical properties and shelf lives of foods. Generally, hydrous foods are susceptive to microbial contamination, as well as to alteration and deterioration such as hydrolysis, souring and browning.
As one means to decrease the moisture in the foods in order to prolong their shelf lives, various dehydration methods have been employed: for example, "sato-zuke (preservation in sugar)" as in the case of "buntan-zuke (a candied citrus fruit buntan)", "shio-zuke (pickling in salt)" as in the case of "takuan-zuke (a pickled Japanese radish)", and drying method as in the case of "funmatsu-miso (powdered soybean paste)" or "funmatsu-kaju (fruit juice powder)".
However, sugar has the disadvantages that its excessive sweetness does not suit the recent preference: that the intake of sugar is a major factor of causing dental caries; and still that an excessive intake of sugar increases blood cholesterol. As to common salt, it has been pointed that its excessive intake is one of the major causes of geriatric diseases such as hypertension and cancer. Thus, physicians advise patients to reduce salt intake as much as possible.
Drying undesirably yields insipid foods because vaporization which occurs during drying inevitably disperses some of the compounds responsible for flavor during the processing steps.
Pharmaceuticals containing a bioactive substance, for example, lymphokines, hormones, vitamins, intact bacterial cell or antibiotics, are produced generally by heat-drying or lyophilizing the bioactive substance along with a large amount of a stabilizer. This is because many bioactive substances are unstable under high moisture conditions.
The stabilizers which have been used are water-soluble polymers such as albumin, casein, gelatin and hydroxylethyl starch.
Dehydration in the presence of these water-soluble polymers, however, has the disadvantage of consuming a relatively large amount of energy, insolubilizing the final product, and inactivating the bioactive substances.